Testing CAPI Images


Goss is a YAML based serverspec alternative tool for validating a server’s configuration. It is used in conjunction with packer-provisioner-goss to test if the images have all requisite components to work with cluster API.

Support Matrix

*For stock server-specs shipped with repo

Amazon Linuxaws
Azure Linuxazure
CentOSaws, ova
Flatcar Container Linuxaws, azure, ova
Ubuntuaws, azure, gcp, ova
Windowsaws, azure, ova

Prerequisites for Running Goss

Goss runs as a part of image building through a Packer provisioner. Supported arguments are passed through file: packer/config/goss-args.json

  "goss_arch": "amd64",
  "goss_download_path": "",
  "goss_entry_file": "goss/goss.yaml",
  "goss_format": "json",
  "goss_inspect_mode": "true",
  "goss_remote_folder": "",
  "goss_remote_path": "",
  "goss_skip_install": "",
  "goss_tests_dir": "packer/goss",
  "goss_url": "",
  "goss_format_options": "pretty",
  "goss_vars_file": "packer/goss/goss-vars.yaml",
  "goss_version": "0.3.16"
Supported values for some of the arguments can be found here.

Enabling the goss_inspect_mode lets you build image even if Goss tests fail.

Manually setup Goss

  • Start a VM from CAPI image
  • Copy complete Goss dir packer/goss to remote machine
  • Download and setup Goss (use version from goss-args) on the remote machine. Instructions
  • Custom Goss version can be installed if testing custom server-specs supported by higher version of Goss.
  • All the variables used in Goss are declared in packer/goss/goss-vars.yaml
  • Add more custom serverspec to corresponding Goss files. Like, goss-command.yaml or goss-kernel-params.yaml
      some_cli --version:
        exit-status: 0
        stdout: [{{ .Vars.some_cli_version }}]
        stderr: []
        timeout: 0
  • Add more custom variables to corresponding Goss file goss-vars.yaml.
    some_cli_version: "1.4.5+k8s-1"
  • Fill the variable values in goss-vars.yaml or specify in --vars-inline while executing Goss in below steps
  • Render the Goss template to fix any problems with parsing variable and serverspec YAMLs
      sudo goss -g goss/goss.yaml --vars /tmp/goss/goss-vars.yaml --vars-inline '{"ARCH":"amd64","OS":"Ubuntu","PROVIDER":"aws", some_cli_version":"1.3.4"}' render
  • Run the Goss tests
      sudo goss -g goss/goss.yaml --vars /tmp/goss/goss-vars.yaml --vars-inline '{"ARCH":"amd64","OS":"Ubuntu","PROVIDER":"aws", some_cli_version":"1.3.4"}' validate --retry-timeout 0s --sleep 1s -f json -o pretty